Question

In an acid-base titration performed to determine the unknown molarity of an acid, 30.2 mL of 0.100 M NaOH was required to neutralize 25.0 mL of H₂SO₄. What is the molarity of the acid?

2NaOH(aq) + H₂SO₄(aq)=Na₂SO₄(aq) + 2 H₂O(l)

Answer 1

The molarity of the acid is 0.0604 M

Step-by-step explanation:

In order to determine the molarity of the unknown acid, we can use the stoichiometry of the balanced chemical equation that represents the titration reaction. The balanced equation is:

H₂SO₄(aq) + 2NaOH(aq) → Na₂SO₄(aq) + 2H₂O(l)

From the equation, we can see that the ratio between H₂SO₄ and NaOH is 1:2. Using this ratio, we can calculate the number of moles of NaOH that reacted with the H₂SO₄:

• Number of moles of NaOH = volume of NaOH (in L) x molarity of NaOH
• Number of moles of NaOH = 0.0302 L x 0.100 M = 0.00302 moles

Since the ratio is 1:2, the number of moles of H₂SO₄ is half the number of moles of NaOH:

• Number of moles of H₂SO₄ = 0.00302 moles / 2 = 0.00151 moles

Finally, we can calculate the molarity of the acid by dividing the number of moles of H₂SO₄ by the volume of acid (in L):

• Molarity of acid = number of moles of acid / volume of acid (in L)
• Molarity of acid = 0.00151 moles / 0.0250 L = 0.0604 M